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      1 /* crypto/des/cfb64ede.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) cryptsoft.com).
      7  * The implementation was written so as to conform with Netscapes SSL.
      8  *
      9  * This library is free for commercial and non-commercial use as long as
     10  * the following conditions are aheared to.  The following conditions
     11  * apply to all code found in this distribution, be it the RC4, RSA,
     12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     13  * included with this distribution is covered by the same copyright terms
     14  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     15  *
     16  * Copyright remains Eric Young's, and as such any Copyright notices in
     17  * the code are not to be removed.
     18  * If this package is used in a product, Eric Young should be given attribution
     19  * as the author of the parts of the library used.
     20  * This can be in the form of a textual message at program startup or
     21  * in documentation (online or textual) provided with the package.
     22  *
     23  * Redistribution and use in source and binary forms, with or without
     24  * modification, are permitted provided that the following conditions
     25  * are met:
     26  * 1. Redistributions of source code must retain the copyright
     27  *    notice, this list of conditions and the following disclaimer.
     28  * 2. Redistributions in binary form must reproduce the above copyright
     29  *    notice, this list of conditions and the following disclaimer in the
     30  *    documentation and/or other materials provided with the distribution.
     31  * 3. All advertising materials mentioning features or use of this software
     32  *    must display the following acknowledgement:
     33  *    "This product includes cryptographic software written by
     34  *     Eric Young (eay (at) cryptsoft.com)"
     35  *    The word 'cryptographic' can be left out if the rouines from the library
     36  *    being used are not cryptographic related :-).
     37  * 4. If you include any Windows specific code (or a derivative thereof) from
     38  *    the apps directory (application code) you must include an acknowledgement:
     39  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  * The licence and distribution terms for any publically available version or
     54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     55  * copied and put under another distribution licence
     56  * [including the GNU Public Licence.]
     57  */
     58 
     59 #include "des_locl.h"
     60 
     61 /* The input and output encrypted as though 64bit cfb mode is being
     62  * used.  The extra state information to record how much of the
     63  * 64bit block we have used is contained in *num;
     64  */
     65 
     66 void des_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
     67 	     long length, des_key_schedule ks1, des_key_schedule ks2,
     68 	     des_key_schedule ks3, des_cblock *ivec, int *num, int enc)
     69 	{
     70 	register DES_LONG v0,v1;
     71 	register long l=length;
     72 	register int n= *num;
     73 	DES_LONG ti[2];
     74 	unsigned char *iv,c,cc;
     75 
     76 	iv=&(*ivec)[0];
     77 	if (enc)
     78 		{
     79 		while (l--)
     80 			{
     81 			if (n == 0)
     82 				{
     83 				c2l(iv,v0);
     84 				c2l(iv,v1);
     85 
     86 				ti[0]=v0;
     87 				ti[1]=v1;
     88 				des_encrypt3(ti,ks1,ks2,ks3);
     89 				v0=ti[0];
     90 				v1=ti[1];
     91 
     92 				iv = &(*ivec)[0];
     93 				l2c(v0,iv);
     94 				l2c(v1,iv);
     95 				iv = &(*ivec)[0];
     96 				}
     97 			c= *(in++)^iv[n];
     98 			*(out++)=c;
     99 			iv[n]=c;
    100 			n=(n+1)&0x07;
    101 			}
    102 		}
    103 	else
    104 		{
    105 		while (l--)
    106 			{
    107 			if (n == 0)
    108 				{
    109 				c2l(iv,v0);
    110 				c2l(iv,v1);
    111 
    112 				ti[0]=v0;
    113 				ti[1]=v1;
    114 				des_encrypt3(ti,ks1,ks2,ks3);
    115 				v0=ti[0];
    116 				v1=ti[1];
    117 
    118 				iv = &(*ivec)[0];
    119 				l2c(v0,iv);
    120 				l2c(v1,iv);
    121 				iv = &(*ivec)[0];
    122 				}
    123 			cc= *(in++);
    124 			c=iv[n];
    125 			iv[n]=cc;
    126 			*(out++)=c^cc;
    127 			n=(n+1)&0x07;
    128 			}
    129 		}
    130 	v0=v1=ti[0]=ti[1]=c=cc=0;
    131 	*num=n;
    132 	}
    133 
    134 #ifdef undef /* MACRO */
    135 void des_ede2_cfb64_encrypt(unsigned char *in, unsigned char *out, long length,
    136 	     des_key_schedule ks1, des_key_schedule ks2, des_cblock (*ivec),
    137 	     int *num, int enc)
    138 	{
    139 	des_ede3_cfb64_encrypt(in,out,length,ks1,ks2,ks1,ivec,num,enc);
    140 	}
    141 #endif
    142